Spatiotemporal urban growth impact on Bucharest metropolitan region climate

This study investigated the influences of urban growth changes and extreme climate events on land surface temperature in relationship with several biophysical variables in Bucharest metropolitan area of Romania through satellite and in-situ monitoring data. Remote sensing data from Landsat TM/ETM/OLI and time series MODIS Terra/Aqua and NOAA AVHRR sensors have been used to assess urban land cover-temperature interactions over 2000 - 2017 period. Time series Thermal InfraRed (TIR) satellite remote sensing data in synergy with meteorological data (air temperature-Ta, precipitations, wind, solar radiation, etc.) have been applied mainly for analyzing land surface temperature (LST) patterns and its relationship with surface landscape characteristics, assessing urban heat island (UHI), and relating urban land cover temperatures (LSTs). Based on these parameters, the urban size dynamics, urban heat island effect (UHI) and the relationships of LST to other biophysical and meteorological parameters (surface albedo, precipitations, wind intensity and direction, air temperature) have been analyzed. Results show that in the metropolitan area ratio of impervious surface in Bucharest increased significantly during investigated period, the intensity of urban heat island and heat wave events being most significant. The correlation analyses revealed that, at the pixel-scale, LST and Ta possessed a strong positive correlation with percent impervious surfaces and negative correlation with vegetation abundances at metropolitan scale respectively. The NDVI was significantly correlated with precipitation. The spatial average air temperatures in urban test areas rise with the expansion of the urban size.